10- “Flower Sword” Vista
Vista has immense strength. He has extraordinary mastery in dual wielding swordsmanship and even Mihawk acknowledged his skills.
In the anime, some of his attacks generate red flower petals, which befits his epithet “Flower Sword”; Vista has so far only produced rose petals, but mentioned that he could produce other types of flower petals as well. Whether this means he is a Devil Fruit user has yet to be determined.
Vista is also capable of using Haki to fight Devil Fruit users. He is at the very least capable of using Busoshoku Haki, as seen when he fought against Akainu.
9- “Diamond” Jozu
Despite his massive body, his speed and reflexes are on par with his brute force.
Jozu has eaten a currently unnamed Paramecia-type Devil Fruit that allows him to transform parts and most likely all of his body, into diamond.
Jozu’s powers give him the ability to greatly increase his offensive and defensive capabilities, as his already strong physical attacks are enhanced by the density of his diamond body.
Jozu also proved himself a proficient user of Busoshoku Haki.
8- Portgas D. Ace
Ace possesses immense physical strength which is supplemented by his extraordinary fighting skills.
He ate the Devil Fruit Mera Mera no Mi, a Logia-type fruit that allows him to become the element of fire and control the flames from his body.
Ace possesses Haoshoku Haki, which he initially had no conscious control over. He first demonstrated the ability at 10 years of age, anyway he has never been seen using Haki apart from during his childhood.
7- Charlotte Cracker
Cracker is physically extremely strong, able to wield Pretzel, a very large sword, while maintaining sufficient speed . He also has shown immense amounts of stamina.
Cracker ate the Bisu Bisu no Mi, a Paramecia-type Devil Fruit that allows him to generate and manipulate biscuits at will.
Cracker models his biscuits into identical, hulking, and lifelike entities complete with weapons. He usually inhabits one of his puppets as a suit of armor, which he uses to mislead his enemies about his real appearance. He can manipulate his puppets’ bodies at will, including granting them extra limbs and weapons.
Cracker has incredible mastery of Busoshoku Haki, which he uses to harden his sword and biscuit armor.
6- Charlotte Smoothie
Smoothie possesses an extremely high level of physical strength and extraordinary durability. She is shown to have a strong will, being able to withstand Big Mom’s Haoshoku Haki and remain conscious from her loud screams.
Smoothie seems to possess a Paramecia-type Devil Fruit ability that allows her to wring and squeeze “juice” out of objects, living or not, as if they were wet table cloths or rags. She can also use the ability on herself to squeeze out poison from within her body, essentially making her immune to its effects.
5- Shiliew of the Rain
His strength is said to be equal to the Chief Warden Magellan. However, since Magellan’s work hours are limited due to his diarrhea, Shiliew was considered more dangerous.
Shiliew is extremely proficient in wielding his nodachi, having used it to kill numerous prisoners of Impel Down, all who were noted to be powerful and dangerous criminals. When his sword was returned to him after a long term imprisonment, Shiliew killed several of his fellow Impel Down officers in a split second, demonstrating extraordinary precision and dexterity in his swordsmanship.
4- Jack the Drought
Jack possesses tremendous strength and endurance, having fought with the Mink Tribe for five days and five nights without taking a break.
He is highly proficient in dual wielding his Shotel blades, able to fight equivalently with Nekomamushi and Inuarashi, the two strongest minks in the Mokomo Dukedom, in one-on-one combat.
Jack has eaten the Ancient Zoan-type version of the Zou Zou no Mi, which allows him to become a mammoth, granting him immense size and strength; in this form, he leveled part of a city by simply swinging his trunk.
3- Marco the Phoenix
Marco ate a Devil Fruit referred to as a Mythical Zoan type, an immensely powerful type of Zoan Devil Fruit which enables him to transform into a phoenix. The additional powers this devil fruit grants may be considered similar to those of Paramecia (the somewhat “superhuman” power that affects the user’s body: regeneration) and Logia (the generation of blue phoenix flames).
This Devil Fruit gives Marco increased physical attributes (as is with all Zoan types) and the rare ability of flight, as well as the possibility of launching aerial attacks.
The fruit’s greatest attribute, however, is that Marco can recover from any damage he accumulates in his human form by reverting to his phoenix, or hybrid phoenix form, or just by summoning blue flames around his body. These blue flames are not hot and they do not burn or spread like normal fire; instead, they are what allow him to heal, and are referred to as the “Blue Flames of Resurrection”
Marco is also capable of using Haki proficiently.
2- Charlotte Katakuri
Charlotte Katakuri has tremendous physical strength, speed and reflexes.
He ate the Mochi Mochi no Mi, a special Paramecia-type Devil Fruit that lets him create, control, and transform into mochi at will.
He has also awakened his Devil Fruit powers, enabling him to transform inorganic material into mochi, enhancing the range of his attacks and capture field.
Katakuri has extraordinary mastery of Kenbunshoku Haki, having trained to such a degree that he can see slightly ahead into the future.
Katakuri is also extremely skilled at using Busoshoku Haki and Haoshoku Haki.
1- Benn Beckman
Benn Beckman has the highest IQ of anyone in the East Blue. Since he is a first mate to a Yonko, he presumably possesses a great deal of strength. During the Battle of Marineford, Admiral Kizaru chose not to fight him, even though he had just fought the First Commander of Whitebeard’s crew and Whitebeard himself. When the Red Hair Pirates arrived at Marineford to stop the war, Beckman was able to climb on to a Marine ship’s mast and sit on it, all the while pointing his flintlock at Kizaru, without the latter noticing.
I would say he is a master in Busoshoku Haki and uses that rifle (armament the bullets) as both a ranged weapon and used as a club.